PHP图片上传异常：提示成功但文件未存入uploads文件夹

Hey Ethan, let's troubleshoot why your uploaded image isn't showing up in the uploads folder even though you get a "Success" message. Here are the key bugs in your code and how to fix them:

1. Mismatched File Input Name #

Your form uses <input type="file" name="profileImage">, but in your PHP code you're referencing $_FILES['file'] everywhere. This means you're not actually accessing the uploaded file data at all. Replace all instances of $_FILES['file'] with $_FILES['profileImage'].

2. Wrong Variable Interpolation #

When splitting the file extension, you used single quotes around $fileName:

$fileExt = explode('.', '$fileName');

Single quotes treat the text as a literal string, so you're splitting the string '$fileName' instead of the actual filename. Remove the quotes:

$fileExt = explode('.', $fileName);

3. Reversed move_uploaded_file Parameters #

The move_uploaded_file function requires the temporary file path as the first argument, and the destination path as the second. You had them backwards:

// Wrong
move_uploaded_file($fileNameNew, $fileDestination);

// Correct
move_uploaded_file($fileTmpName, $fileDestination);

4. Invalid uniqid Parameter #

The second parameter for uniqid() is a boolean, but you passed a string 'true'. Change it to the boolean true:

$fileNameNew = uniqid('', true).".".$fileActualExt;

5. Unrealistic File Size Limit #

Your current limit is $fileSize > 2000 (only 2KB), which is way too small for most images. Update it to a reasonable size, like 2MB:

elseif($fileSize > 2 * 1024 * 1024){ // 2MB in bytes
    echo "File is too big! Maximum size is 2MB.";
}

Fixed PHP Code #

if(isset($_POST['uploadImage'])){ 
    $file = $_FILES['profileImage']; 
    $fileName = $_FILES['profileImage']['name']; 
    $fileTmpName = $_FILES['profileImage']['tmp_name']; 
    $fileSize = $_FILES['profileImage']['size']; 
    $fileError = $_FILES['profileImage']['error']; 
    $fileType = $_FILES['profileImage']['type']; 

    $fileExt = explode('.', $fileName); 
    $fileActualExt = strtolower(end($fileExt)); 

    $allowed = array('png', 'jpg', 'jpeg', 'PNG', 'JPG', 'JPEG'); 

    if(!$fileError == 0){ 
        echo "There was an error uploading this image!"; 
    } elseif($fileSize > 2 * 1024 * 1024){ 
        echo "File is too big! Maximum size is 2MB."; 
    } else{ 
        $fileNameNew = uniqid('', true).".".$fileActualExt; 
        $fileDestination = "uploads/".$fileNameNew; 
        move_uploaded_file($fileTmpName, $fileDestination); 
        echo "Success"; 
    } 
} 

Fixed Form Code #

Add proper closing structure for clarity:

<form action="my-account.php" method="post" enctype="multipart/form-data">
    Upload a profile image: 
    <input type="file" name="profileImage"><br>
    <input type="submit" name="uploadImage" value="Upload">
</form>

Final Checks #

• Make sure the uploads folder exists in the same directory as my-account.php.
• Ensure the uploads folder has write permissions (set to 755 or 777 depending on your server configuration).

内容的提问来源于stack exchange，提问作者Ethan